VALIDATION OF A NOVEL PARTIAL REBOA DEVICE IN A SWINE HEMORRHAGIC SHOCK MODEL: FINE TUNING FLOW TO OPTIMIZE BLEEDING CONTROL AND REPERFUSION INJURY

Dominic Forte, Woo S Do, Jessica B Weiss, Rowan R Sheldon, John P Kuckelman, Benjamin A Cook, Tiffany C Levine, Matthew J Eckert, Matthew J Martin

J Trauma Acute Care Surg 2020 Apr 8; Online ahead of print

Objectives: Partial restoration of aortic flow during REBOA is advocated by some to mitigate distal ischemia. Our lab has validated the mechanics and optimal partial REBOA flow rates using a prototype device (pREBOA). We hypothesize that pREBOA will increase survival when compared to full REBOA (fREBOA) in prolonged non-operative management of hemorrhagic shock.

Methods: 20 swine underwent placement of aortic flow probes, zone 1 REBOA placement, and 20% blood volume hemorrhage. They were randomized to either solid organ (SOI) or abdominal vascular (AVI) injury. The pREBOA arm (10 swine) underwent full inflation for 10min, then deflation to a flow rate of 0.5L/min for 2hr. The fREBOA arm (10 swine) underwent full inflation for 60min, followed by deflation/resuscitation. The primary outcome is survival, secondary outcomes are serologic/pathologic signs of ischemia-reperfusion injury and quantity of hemorrhage.

Results: 2/10 swine survived in the fREBOA group (2/5 SOI, 0/5 AVI) v. 7/10 surviving in the pREBOA group (3/5 SOI, 4/5 AVI). Survival was increased (p=.03) and hemorrhage was higher in the pREBOA group (SOI 1.36±.25kg v. 0.70±.33kg, p = 0.007; 0.86±.22kg v. 0.71±.28kg, not significant). Serum evidence of ischemia was greater with fREBOA, but this was not significant (e.g. Lactate 16.91±3.87 mg/dL v. 12.96±2.48 mg/dL at 120min, not significant). Swine treated with pREBOA that survived demonstrated trends towards lower ALT, lower potassium, and higher calcium. The potassium was significantly lower in survivors at 60min and 90min time points (5.97±0.60 v. 7.53±0.90, p=.011; 6.67±0.66 v. 8.15±0.78, p=.029). Calcium was significantly higher at 30min, 60min, 90min (8.56±0.66 v. 7.50±0.40, p=.034; 8.63±0.62 v. 7.15±0.49, p=.019; 8.96±0.64 v. 7.00, p=.028).

Conclusion: Prolonged pREBOA at a moderate distal flow rate provided adequate hemorrhage control, improved survival, and had evidence of decreased ischemic injury versus fREBOA. Prophylactic aggressive calcium supplementation may have utility prior to and during the reperfusion phase.

Study type: Basic Science (Original Article) LEVEL OF EVIDENCE: III.